Imaging apparatus having framing assist control

ABSTRACT

In an imaging apparatus having framing assist control, a controller controls a change speed of the display angle of view changed by a second or a third instruction member faster than the change speed of the display angle of view changed by a first instruction member. The first instruction member is configured to issue an instruction regarding a change of a display angle of view and a change direction of the display angle of view. The second instruction member is configured to issue an instruction to change the display angle of view displayed on the monitor to a wide-angle side by a predetermined amount. The third instruction member is configured to issue an instruction to change the display angle of view displayed on the monitor to the display angle of view before the display angle of view is changed by the second instruction member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of co-pending U.S. patent applicationSer. No. 13/196,253, filed Aug. 2, 2011, which claims foreign prioritybenefit of Japanese Patent Application No. 2010-176136 filed Aug. 5,2010, both of which are hereby incorporated by reference herein in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus, such as a digitalcamera including an optical zoom function and an electronic zoomfunction.

2. Description of the Related Art

Conventionally, for the purpose of quickly capturing an image of anobject and performing image processing, a camera system capable ofperforming quick and accurate adjustment of an angle of view by anoperation of a zoom lever is required. Japanese Patent ApplicationLaid-Open No. 2004-252370 discusses an improvement in operability ofsuch a zoom lever operation by using a camera system that eliminates theneed for fine adjustment of the angle of view which has been adjusted bythe zoom lever or a zoom ring. According to the camera system, a userdesignates a region to be enlarged by a frame if the user desires tozoom-in. On the other hand, if the user desires to zoom back, the userdetermines the reduction ratio after confirming the reduced image. Then,the zooming is automatically performed according to a predeterminedoperation.

The zooming speed of the camera system discussed in Japanese PatentApplication Laid-Open No. 2004-252370 can be set by the user to adesirable speed in advance of the operation. However, the setting methodof the speed is not discussed in Japanese Patent Application Laid-OpenNo. 2004-252370.

Generally, the angle of view is difficult to adjust if a high power zoomlens is used since the camera shake has a significant effect on theimaging. Thus, the object may be frequently lost even if the angle ofview is set. In such a situation, it is difficult to quickly change theangle of view to the wide-angle by the zoom lever and then change theangle of view back again after capturing the object.

On the other hand, if a framing button is provided in addition to thezoom lever, the user can easily perform the framing during the high zoommagnification imaging by pressing the framing button. When the framingbutton is pressed, the current zoom position is stored and the zoom isdriven to a wide-angle position which is acquired based on the currentzoom ratio. When, the user releases the framing button, the position ischanged back to the stored zoom position. In the following description,this function is referred to as the “framing assist” function.

Unlike the operation by the zoom lever, the target zoom position of theframing assist function is determined before the drive. Thus, amissoperation such as overshooting does not occur even if the zooming isperformed at a high speed. Accordingly, the zooming can be controlled athigh speed. However, if the camera is in a moving image mode, unlike theangle of view adjustment of the imaging of a still image, the continuityof the recorded video image becomes important.

There are two types of operations concerning the zoom framing assistfunction. One function is used for driving the zoom in the wide-angledirection to capture the object in the angle of view. The other functionis used for zooming in on the captured object. Since driving the zoom inthe wide-angle direction (the former function) is used for capturing theobject, high speed zooming in the wide-angle direction is required. Incontrast, for zooming in on the captured object, a smooth operation isgiven priority in changing the angle of view rather than the speed ofthe operation with respect to the latter function so that the capturedobject is not lost.

SUMMARY OF THE INVENTION

The present invention is directed to an imaging apparatus that cancontrol zooming at an optimum zoom speed appropriate for an operation inzoom imaging and improve the convenience for a user at high zoommagnification imaging.

According to an aspect of the present invention, an imaging apparatusincludes a monitor configured to display an image, a first instructionmember which is operable by a user and is configured to issue aninstruction corresponding to a change of a display angle of view of theimage displayed on the monitor and a change direction of the displayangle of view, a second instruction member which is operable by the userand is configured to issue an instruction to change the display angle ofview displayed on the monitor to a wide-angle side by a predeterminedamount, a third instruction member which is operable by the user and isconfigured to issue an instruction to change the display angle of viewdisplayed on the monitor to the display angle of view before the displayangle of view is changed by the second instruction member, and acontroller configured to control a change speed of the display angle ofview changed by the second or the third instruction member faster thanthe change speed of the display angle of view changed by the firstinstruction member.

Further features and aspects of the present invention will becomeapparent from the following detailed description of exemplaryembodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate exemplary embodiments, features,and aspects of the invention and, together with the description, serveto explain the principles of the invention.

FIG. 1 illustrates a system configuration of an imaging apparatusaccording to an exemplary embodiment of the present invention.

FIG. 2 is a flowchart illustrating zoom control performed by a zoomlever operation according to the exemplary embodiment.

FIG. 3 is a flowchart illustrating framing assist control according tothe exemplary embodiment.

FIG. 4 illustrates an example of a relation among an operation, animaging mode, and a zoom control speed according to the exemplaryembodiment.

DESCRIPTION OF THE EMBODIMENTS

Various exemplary embodiments, features, and aspects of the inventionwill be described in detail below with reference to the drawings.

FIG. 1 illustrates an example of a configuration of a digital camera asan exemplary embodiment of an imaging apparatus according to the presentinvention. A system control unit 1, such as a microprocessor, includes abuilt-in non-volatile memory or a removable non-volatile memory andexecutes a program recorded in the memory to realize the processingaccording to at least one of the exemplary embodiments described below.Further, the digital camera includes a network interface (I/F) (notshown) and can execute a program on a non-illustrated digital processor(server) residing in the network. Thus, at least part of the presentinvention may be implemented by executing a program on a network.

A power switch 2 is used for turning on/off the power of the digitalcamera. A mode switch 3 is used for changing imaging modes of thedigital camera. Imaging modes include but are not limited to a stillimage mode, a moving image mode, and a reproduction mode . The stillimage mode and the moving image mode are used for processing imagingdata and recording the obtained processed image in an image recordingunit as a still image and a moving image, respectively. The reproductionmode is used for processing an image recorded in the image recordingunit and outputting (displaying) the processed image onto an imageoutput (display) unit. In the description below, the still image modeand the moving image mode are referred to as the imaging mode. A releaseswitch 4 is used to instruct recording of the imaging data into theimage recording unit in the imaging mode.

An imaging unit 5 performs analog-to-digital (AD) conversion on an imagesignal exposed by a non-illustrated image sensor and outputs theconverted signal. An image display unit 6 serves as a monitor to display(reproduce) the image data stored in a display memory 7 on a displaydevice such as a liquid crystal display (LCD).

An image processing unit 8 performs compression and expansion processingor development processing on the imaging data obtained by the imagingunit 5 or the image data recorded in the image recording unit 10. Animage processing memory 9 is used when the image processing unit 8performs image processing.

An image recording unit 10 records the image data which has beencaptured. A zoom lever 11 is used for changing a drive direction or aspeed of an optical zoom and an electronic zoom according to itsoperation direction or the amount of operation. A framing button 12 isused for temporarily driving the zoom to a wide-angle direction. Theframing button 12 is pressed when the object is lost during the zoom. Azoom lens unit 13 and a focus lens unit 14 include a drive motor.

The portions related to the present exemplary embodiment included in thecontrol block of the system control unit 1 will be described. The systemcontrol unit 1 includes a drive control unit 15, a reproduction controlunit 16, and an imaging control unit 17 all of which operate accordingto various switch operations and control programs executed by the systemcontrol unit 1. The imaging control unit 17 performs control of theimaging processing sequence when the camera is in the imaging mode. Thereproduction control unit 16 performs control of the image reproductionprocessing sequence when the camera is in the reproduction mode. Thedrive control unit 15 performs control of the drive sequence of the zoomlens unit 13, the focus lens unit 14, and so on.

The imaging mode of the present exemplary embodiment is used not onlyfor recording an image but also for executing a through display functionwhich is a function for displaying an image captured by the imaging unit5 on the image display unit 6 in real time (e.g., in preview mode). Inaddition to the optical zoom function for driving the zoom lens, theimaging mode includes the electronic zoom function for clipping aportion of the captured image and displaying an enlarged image of theclipped image.

The operation according to the exemplary embodiment of the presentinvention will be described below with reference to FIGS. 2 to 4.

According to the present exemplary embodiment, the zoom lens controlperformed by the drive control unit 15 and the electronic zoom controlperformed by the imaging control unit 17 are not differentiated andreferred to as the zoom control in the description below.

If the zoom lever 11 is operated, the system control unit 1 performs thezoom control based on the operation direction and the amount ofoperation of the zoom lever 11. FIG. 2 is a flowchart illustrating thezoom control operation.

The zoom control performed according to the zoom lever operation will bedescribed with reference to FIG. 2. In step S101, the system controlunit 1 determines a zoom control speed V1 (hereinafter referred to asthe speed V1) according to the imaging mode and the amount of operationof the zoom lever 11. In step S102, the system control unit 1 starts thezoom drive in the direction corresponding to the zoom lever operationdirection at the speed V1. Specifically, as illustrated in FIG. 4 (rowsNo. 1-3), when the imaging mode is a still image mode and the zoom leveroperation amount is small, the system control unit 1 performs the zoomdrive in the direction corresponding to the zoom lever operationdirection at a LOW speed V1. Alternatively, when the imaging mode is amoving image mode and the zoom lever operation amount is small, thesystem control unit 1 performs the zoom drive in the directioncorresponding to the zoom lever operation direction at an EXTREMELY LOWspeed V1. Similar operations occur at step S102 when the zoom leveroperation amount is medium and large, respectively. Accordingly, it canbe seen from FIG. 4, that when the imaging mode is a still image mode,the system control unit 1 performs the zoom drive corresponding to thezoom lever operation amount a speed V1 higher than a speed V1 when theimaging mode is a moving image mode.

In step S103, the system control unit 1 determines whether the zoomposition is at the telephoto end or at the wide-angle end of the drivedirection. If the zoom position reaches the telephoto end or thewide-angle end (YES in step S103), the processing proceeds to step S105.If the zoom position is neither at the telephoto end nor at thewide-angle end (NO in step S103), and further it is determined that thezoom lever operation is stopped (YES in step S104), the processingproceeds to step S105. In step S105, the system control unit 1 stops thezoom drive. On the other hand, if the zoom position is anywhere betweenthe telephoto end the wide-angle end (NO in step S103) and the zoomlever operation is determined to be active (NO instep S104), then instep S106, the system control unit 1 performs the zoom drive whilechanging the speed V1 according to the change in the operation amount ofthe zoom lever.

If the user presses (turns ON) the framing button 12, the system controlunit 1 performs the framing assist control. FIG. 3 is a flowchartillustrating the framing assist control.

The framing assist control will be described below with reference toFIG. 3. Instep S201, when the framing button 12 is pressed (turned ON),the system control unit 1 stores a current zoom position P0 (the zoomposition when the framing button 12 is pressed) in the memory, acquiresa zoom position P1 corresponding to a focal length which is apredetermined amount shorter than the focal length of the current zoomposition P0 (in other words, a position a predetermined amount on thewide-angle end side), and stores the zoom position P1 in the memory.

In step S202, the system control unit 1 determines a speed V2 accordingto whether the imaging mode is the still image mode or the moving imagemode. In step S203, the system control unit 1 performs the zoom drive tothe wide-angle direction at the speed V2 set in step S202. Specifically,as illustrated in FIG. 4 (row No. 4), when the framing button is ON andthe imaging mode is the still image mode, the system control unit 1performs the zoom drive to the wide-angle direction at the speed V2(extremely high speed), which is the highest speed available for zoomdrive. Alternatively, when the framing button is ON and the imaging modeis the moving image mode, the system control unit 1 performs the zoomdrive to the wide-angle direction at the speed V2 (medium speed), whichis lower than the highest speed available for zoom drive.

In step S204, the system control unit 1 determines whether the zoomposition is at the zoom position P1 or at the wide-angle end. If thezoom position is either at the wide-angel end or at the zoom position P1(YES at step S204), the process advances to step S206. If the zoomposition is neither at the wide-angel end nor at the zoom position 1 (NOat step S204), the process advances to step S205.

In step S205, the system control unit 1 determines whether the framingbutton 12 is released (turned OFF) during the zoom drive. If the framingbutton is released (YES in step S205), the processing proceeds to stepS206. If the framing button is not released (NO in step S205), thesystem control unit 1 continues the zoom drive to the wide-angledirection, and again determines whether the zoom position is at the zoomposition P1 or at the wide-angle end in step S204.

In step S206, once the zoom position reaches one of the wide-angel endand the zoom position P1 or when the framing button is released, thesystem control unit 1 stops the zoom drive. The zoom stop position atthat time (step S206) will be either the zoom position P1 or thewide-angle end. In other words, when the framing button is released, thesystem control unit 1 stops the zoom drive after returning the zoom tozoom position P1. That is, when, the user releases the framing button,the position is changed back to the stored zoom position P1.

In step S207, the system control unit 1 determines whether the framingbutton 12 is released (turned OFF). If the framing button 12 is released(YES in step S207), the processing proceeds to step S208. In step S208,the system control unit 1 determines a speed V3 according to whether theimaging mode is the still image mode or the moving image mode.

In step S209, the system control unit 1 performs the zoom drive in thetelephoto direction to the zoom position P0 that is the position beforethe driving by the “ON” operation of the framing button 12. At thispoint it is determined in step S210 that the zoom position is at thezoom position P0.

An example of the relations among the zoom control speeds V1, V2, and V3which are the key point of the present exemplary embodiment will bedescribed below with reference to FIG. 4.

In FIG. 4, Nos. 1 to 3 illustrate speeds used as the zoom control speedV1 when the zoom lever is operated. No. 4 illustrates the zoom controlspeed V2 when the zoom is driven in the wide-angle direction when theframing button 12 is pressed (turned ON). No. 5 illustrates the zoomcontrol speed V3 when the zoom is driven back to the position P0 of thezoom (stored before the framing button has been pressed), upon therelease (OFF) of the framing button 12.

According to the framing assist control, at the time the framing button12 is pressed and the operation is started, a target value which is apredetermined value on the wide-angle side is set. Thus, the user doesnot need to care about miss operation such as overshooting. Accordingly,an extremely high speed, which is faster than the zoom control speedrealized by the operation of the zoom lever, can be set as illustratedin No. 4. In this way, when the zooming is controlled by the framingbutton 12, the speed V2 faster than the high zoom speed in the range ofthe zoom control speed V1 when the zooming is executed according to thezoom lever 11 can be set to control the zoom. Thus, the object ofinterest can be quickly captured.

Accordingly, the lost object can be quickly captured in the angle ofview. Further, when the imaging mode is the moving image mode and thezoom is controlled by the framing button 12, a speed equal to themaximum zoom control speed according to the zoom lever 11 will be used.In this manner, continuity of the moving image to be recorded can bemaintained.

Further, as illustrated in No. 5, when the captured object is zoomed-inaccording to the release of the framing button (OFF), the zoom drive isperformed by a speed slower than the speed which is used when thezooming is driven in the wide-angle direction according to the pressingof the framing button. Thus, once the object is captured, the objectwill not be lost due to abrupt change in the angle of view.

Although the optical zoom which realizes the zoom operation by drivingthe zoom lens and the electronic zoom which realizes the zoom byenlarging a clipped region of the image are not distinguished in thedescription above, if the zoom speeds of the optical zoom control andthe electronic zoom control are different, there will be no problem.

According to the present exemplary embodiment, the still image mode andthe moving image mode are described separately. In recent years, thereare cameras which can record a moving image in the still image mode. Ifsuch cameras are used, the mode which is used when the moving image isrecorded will correspond to the moving image mode of the presentexemplary embodiment.

According to the present exemplary embodiment, the zoom lever 11 is usedas a first instruction member of the present invention. Further, theframing button 12 to be turned on is used as a second instruction memberand the framing button 12 to be turned off is used as a thirdinstruction member of the present invention. However, the operationmembers of the present invention are not limited to such members andoperation members of any form can be used.

The exemplary embodiments of the present invention are not limited tothe above-described embodiments and various modifications and changescan be implemented so long as they are within the scope of the presentinvention.

For example, the angle of view of the above-described embodiment ischanged by controlling the zoom lens unit 13. The change of the angle ofview can also be realized by the electronic zoom.

According to the present invention, the zoom can be controlled in anoptimum zoom speed according to an operation to be performed in the zoomimaging. Thus, the user convenience can be enhanced when the userperforms the high zoom magnification imaging.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures, and functions.

What is claimed is:
 1. A zoom control apparatus comprising: a monitorconfigured to display an image; a first zooming controller which isconfigured to change an angle of view of the image displayed on themonitor based on user operation of a first operation detecting member;and a second zooming controller which is configured to change the angleof view displayed on the monitor to a wide-angle side by a predeterminedamount based on user operation of a second operation detecting memberdifferent from the first operation detecting member, wherein a changespeed of the angle of view changed by the second zooming controller isfaster than a change speed of the angle of view changed by the firstzooming controller.
 2. The zoom control apparatus according to claim 1,wherein the second zooming controller is configured to, at thewide-angle side, change the angle of view displayed on the monitor to atelephoto-angle side by a predetermined amount based on a useroperation.
 3. The zoom control apparatus according to claim 2, whereinthe change to the telephoto side by the second zooming controller is achange into an angle of view which is before changing the angle of viewby the second zooming controller.
 4. The zoom control apparatusaccording to claim 2, wherein the second zooming controller isconfigured to control the change speed of the angle of view changed tothe wide-angle side faster than the change speed of the angle of viewchanged to the telephoto-angle side.
 5. The imaging apparatus accordingto claim 1, wherein a stop position of the angle of view when the angleof view is changed by the second zooming controller is changed accordingto the angle of view when the instruction is issued to change the angleof view.
 6. The imaging apparatus according to claim 1, wherein thepredetermined amount is changed according to the angle of view when theinstruction is issued to change the angle of view.
 7. The imagingapparatus according to claim 1, further comprising: an imaging modeselection unit configured to select one of a still image mode and amoving image mode, wherein the second zooming controller is configuredto control a speed at which an angle of view is changed to wide-angleside by the predetermined amount in the moving image mode equal to themaximum speed at which the angle of view is changed by the first zoomingcontroller.
 8. The imaging apparatus according to claim 1, furthercomprising: an imaging mode selection unit configured to select one of astill image mode and a moving image mode, wherein the second zoomingcontroller is configured to control a speed at which an angle of view ischanged to wide-angle side by the predetermined amount in the stillimage mode faster than a speed at which the angle of view is changed towide-angle side by the predetermined amount in the moving image mode. 9.The imaging apparatus according to claim 1, further comprising: animaging mode selection unit configured to select one of a still imagemode and a moving image mode, wherein the second zooming controller isconfigured to control a speed at which an angle of view is changed totelephoto-angle side by the predetermined amount in the still image modefaster than a speed at which the angle of view is changed totelephoto-angle side by the predetermined amount in the moving imagemode.
 10. The imaging apparatus according to claim 1, furthercomprising: an imaging mode selection unit configured to select one of astill image mode and a moving image mode, wherein, when the imaging modeselection unit selects the still image mode, the second zoomingcontroller controls a speed at which an angle of view is changed to thewide-angle side by the predetermined amount in the still image modefaster than a speed at which the angle of view is changed to thewide-angle side by the predetermined amount in the moving image mode.11. A method of controlling an imaging apparatus comprising: displayingan image on a monitor; causing a first zooming controller to change anangle of view of the image displayed on the monitor based on useroperation of a first operation detecting member; and causing a secondzooming controller to change the angle of view displayed on the monitorto a wide-angle side by a predetermined amount based on user operationof a second operation detecting member different from the firstoperation detecting member, wherein a change speed of the angle of viewchanged by the second zooming controller is faster than a change speedof the angle of view changed by the first zooming controller.